1. Field of the Invention
This invention relates to on-chip communication. In particular, the invention relates to on-chip communication between plural on-chip components across a communication bus having plural tracks.
2. Description of the Related Art
Traditional integrated circuit chips, also known as computer chips, are dedicated to a single function, with the chips attached to one another at a circuit board level. However, the number and types of circuits that can be place on a computer chip has continued to advance at a rapid pace. It is now possible to include circuits for many different functions on a single chip to create a complete “system on a chip.”
Designing systems on a chip can be daunting. In particular, providing for communication between different on-chip integrated components can be difficult. Furthermore, traditional design approaches tend not to be scalable to systems that involved increasing numbers of on-chip components.
Each function on multi-functional single chip is implemented by an independently operating module. To function, each module exchanges data with another module. These modules function as a data transfer pair. As the number of functions on a single chip increases, multiple data transfer pairs are needed to simultaneously transfer data. In a traditional time domain shared bus, only one data transfer pair can transfer data on the shared bus at any given time. Thus, in the event that multiple data transfer pairs need to simultaneously transfer data, only one pair can have access to the bus at a time and the other pairs must wait. In a switch fabric, each module has a communication path from itself to all other modules; and thus, if the target module is not currently engaged in a data transfer, it can accept data from an initiator without contention with other data transfers that may be simultaneously occurring.